Color Centers Formation in Lithium Fluoride Nanocubes Doped with Different Elements

Figure 2

SEM images of the as-synthesized nanocubes of LiF doped with Tb at different concentrations: (a) 0.1 mole% (b) 0.2 mole%, (c) 0.5 mole%, and (d) 1 mole%.

(a)

(b)

(c)

(d)